Curing of photosensitive surfaces involves monitoring radiant light emitted from solid-state lighting devices such as light emitting diodes (LEDs) on to the photosensitive surfaces in order to verify the operation and performance of the lighting devices. Conventionally, a lighting system includes a light sensing device such as a photodiode positioned as close as possible to the LEDs in order to detect the maximum amount of light emitted from the solid-state lighting devices. For example, the photodiode may be located directly on an array of LEDs in order to measure the emitted light intensity.
The inventors herein have recognized potential issues with the above lighting systems. Namely, the photosensitive surfaces may have reflective properties that cause an amount of light to be reflected back to the LED array and the photodiode. When light reflected from the photosensitive surface back to the LED array and the photodiode, herein referred to as retro-reflected light, is sensed by the photodiode, it causes errors in the measurement of the emitted light. Furthermore, locating the photodiode in close proximity to the LEDs, such as directly on the LED array, makes the lighting system most susceptible to retro-reflected light detection, thereby significantly reducing operation and performance of the lighting system. Further still, measurement errors caused by retro-reflected light at the photodiode can cause lighting system control problems when the control of the LED array is based on the photodiode measurements.
One approach that at least partially addresses the aforementioned issues includes a method comprising: supplying light from a light emitting device principally along a first axis; sensing the light energy with a light sensing device oriented along a second axis, wherein the second axis is oriented substantially orthogonally to the first axis; and adjusting the light energy in response to the sensed light energy.
In another example, a method may comprise: supplying light energy from a light emitting device along a first axis for curing a curable work piece; sensing the light energy via a light sensing device oriented along a second axis substantially orthogonal to the first axis; and adjusting the curing of the work piece in response to the sensed light energy.
In another example, a lighting system may comprise: a light emitting device oriented to emit light energy principally along a first axis for curing a curable work piece; a light sensing device oriented along a second axis substantially orthogonal to the first axis for measuring the light energy emitted from the light emitting device; and a controller, including non-transitory executable instructions to adjust the curing of the work piece in response to the measured light energy.
In this manner, the technical effect of reducing an amount of retro-reflected light at the light sensing device, reducing measurement error of the light sensing device, and increasing control and overall performance of the lighting system can be achieved.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.